Block 1 - Immunology Flashcards
What is considered “natural/native” immunity?
Innate Immunity
What is considered “acquired, induced, or specific immune response”?
Adaptive Immunity
What is a non-specific, general recognition and response to “foreign” substance?
innate host response
What are the two types of “barriers” that belong to innate host response/innate immunity?
physical and chemical
What is a “specific” immune response to a “foreign” substance?
adaptive immunity
What is a foreign substance, such as a microorganism, foreign blood cell, cells of transplanted organs, or toxins; which trigger an immune response?
antigen
Antibodies are also known as _____________.
immunoglobulins
What is the basic shape of antibodies/immunoglobulins?
“Y” shape
What portion of the antibody is antigen-specific and binds to a specific site on antigen molecules and assists in inactivating the antigen by attaching to it?
the FAB (Fragment Antigen-Binding)
What process does this image depict?
phagocytosis
Antibodies/Immunoglobulins are categorized into these five classes: Ig___, Ig___, Ig___, Ig___, Ig____.
IgA / IgD / IgE / IgG / IgM
These are certain white blood cells that ingest and digest invading microbes.
phagocytes
These are specialized cells located in various tissues that help initiate the immune response by recognizing, “processing” and presenting antigens (Ag) to other cells of the immune system.
dendritic cells
What type of cell is below?
dendritic cell
What cells originate in the bone marrow and mature into various cells in the circulating blood?
Stem cells
What type of cell is an erythrocyte?
a red blood cell
What type of cell is a leukocyte?
a white blood cell
What are the five types of white blood cells?
The basophil, eosinophil, neutrophil, lymphocyte and monocyte
What type of white blood cell is involved in the inflammatory process (.5-1% of WBCs)?
basophil
What type of white blood cell is involved in allergic responses (1-5% of WBCs)?
Eosinophils
What type of white blood cell is the primary phagocytic cell?
neutrophil
What type of white blood cell is phagocytic, mature at the rate of 10^10 per day, circulate about 6-10 hours then adhere to the endothelium of blood vessels and wait to respond to inflammation?
Neutrophils
What type of cells are CELL 1 / CELL 2 / CELL 3?
Erthrocyte, eosinophil and monocyte
What white blood cell is moderately phagocytic and matures into macrophages and dendritic cells that respond to inflammation signals (2-8%)?
Monocyte
What white blood cell is precommitted during maturation to respond to specific antigens (25-40%)?
lymphocytes
What are the three types of lymphocyte?
T-Cell / B-Cell / Natural Killer Cell
The average lymphocyte completes a cycle of circulation through the blood and the lymphatic system in what timeframe?
1 to 2 days
What percentage of lymphocytes within the body is present in the circulating blood?
1%
The remaining lymphocytes that are not circulating through the blood are found adhered to the inside of what circulatory / lymphatic system structure(s)?
the blood and lymphatic vessels
What are large phagocytic cells which mature from monocytes?
macrophages
What type of phagocytic cell possesses many broad-specficity receptors enabling it to capture a wide range of pathogens?
macrophage
What two characteristics allow macrophages to be a “major line of defense against invading microbes and abnormal or defective host cells”?
phagocytosis and antigen presentation
What type of immune response cell can serve as an antigen-presenting cell (APC)?
macrophage, dendritic cell, B cell
What type of tissue is where antigens interact with cells of the immune system?
Lymphoid tissue
In what two areas of the immune system do antigens come into contact with cells of the immune system in a “percolating/meandering” manner?
the lymph nodes and spleen
True or False:
Lymphatic fluid contains antigens and antigen-presenting cells that slowly flow through lymph nodes, where the antigens encounter and activate pre-committed erythrocytes in response to local or regional infections.
False; the antigens encounter lymphocytes - not erythrocytes
Fill in the blank:
_____-borne antigens meander through the spleen cells with Antigen-Presenting Cells where they encounter and activate precommitted lymphocytes in response to systemic infections.
Blood-borne
True or False:
Antigens are relatively small molecules made up of usually protein with complex 3-D configuration.
False; they are relatively large
True or False:
Sometimes even large, complex carbohydrate molecules can be antigenic.
True
Greater complexity of the antigen is associated with a greater ability of the immune system to take what action?
recognize it and respond to it
In the figure below, the arrow is pointing to what portion of the antigen?
What is the role of this site?
The epitope
The epitope is the specific part of the immunogen that specifies or determines the exact antibody to be produced.
When a specific antibody or T-Cell receptor matches/binds with an antigen, the portion it is matching/binding to structurally on the antigen is defined as the __________.
epitope
Quality of the epitope is based upon what two factors?
Its exposure to the immune system
&
the 3 dimensional shape of the molecule
What are the proteins on the surface of tissue and blood cells that identify cells belonging to a specific individual?
Major Histocompatibility Complex Proteins
Antigens are recognized by __ cells and __ cells when they are presented on _ _ _ molecules.
T & B-cells; MHC
What class and protein are the structures below?
Class I - MHC: one amino acid chain
Class II - MHC: two amino acid chains
Dendritic cells, macrophages, and B-Cells share similar characteristics as they all have two amino acid chains, making them what class of what major immune system protein?
Class II, Major Histocompatibility Complex proteins
What class and type of protein is found on virtually every cell in the body?
Class I, MHC proteins
What is the exception for when an immune response does not occur if blood or tissue of another person is sensed as being “non-self”?
The exception is only for identical twins
What are the specialized cells located primarily in tissues where they are exposed to the external environment and they participate in initiating antigen recognition and immune response?
Dendritic cells
What portion of the body are Langerhans cells found?
The skin
The intestines contain what type of cells that participate in initiaiting antigen recognition and immune response?
The intestine
Where are these dendritic cells found within the body:
Cell Type
a. ) Langerhans cells
b. ) Intestine
c. ) Alveolar macrophage
d. ) Kupffer cells
e. ) Microglial cells
f. ) Interdigitating Dendritic Cells
a. ) Langerhans cells: skin
b. ) Intestine: intestine
c. ) Alveolar macrophage: lung
d. ) Kupffer cells: liver
e. ) Microglial cells: brain
f. ) Interdigitating Dendritic Cells: lymph nodes and spleen
What type of cell posseses these characteristics:
a. Capture foreign antigens – Spidery shape of dendrites (like tentacles) possess large surface area which facilitates capturing foreign antigens
b. Process foreign antigens and place peptides onto MHC-II molecules on cell surface
c. Migrate through the blood and lymph to spleen and lymph nodes to present antigens to cells of the immune system
d. Highly efficient at presenting antigens.
Dendritic Cells
Chemicals in serum & tissue respond to antigen presence - kinins, fibrinopeptides, clotting factors, lysozyme, histamine, cytokines, etc.
a. Vasodilation and increased permeability of capillaries; blood vessels become “leaky”
b. “Call” phagocytic white blood cells to move to the site of invasion and assist in killing (removing) the invading microbe
c. Phagocytosis occurs, often producing pus (debris of phagocytes and bacteria) & swelling.
What is this repsonse defined as?
innate host response (inflammatory response)
These physical and chemical barriers are a part of what reponse?
(1) Skin & mucous
(2) Certain proteins in blood and from specific tissue cells
(3) Phagocytosis
The innate host response
What are the two primary cells invovled in phagocytosis?
What is the movement of a phagocyte toward the site of inflammation/intrusion; “called” by cellular products or complement components?
macrophage / neutrophil
Chemotaxis
What are the characteristic actions of phagocytosis?
chemotaxis - adherence - ingestion - digestion
What are the portions of the cytoplasm that contain powerful digestive enzymes and bactericidal substances within the lysosome?
When a lysosome combines with a phagosome they form what cell in which the foreign material is digested?
cytoplasmic granules
phagolysosomes
Within the characteristics of Lymphocytes:
What are the three types?
1)
2)
3)
Lymphocytes are identified and differentiated by _______ __ _________.
a. T-lymphocytes (T-cells)
b. B-lymphocytes (B-cells)
c. Natural Killer (NK) cells
Clusters of Differentiation
These are characteristics of what immune system structure?
a. These are protein complexes on the surface of lymphocytes
b. Serve as receptors or attachment sites
c. Identify different stages of lymphocyte development and different functions of the cell
Clusters of Differentiation
Fill in the blank when necessary.
Regarding the Development of Lymphocyte Specificity for Antigens:
Immature lymphocytes undergo a large number of variable ______ recombinations for surface receptor molecules resulting in each lymphocyte having the capability to react with (respond to) a single type of antigen.
(2) Each mature, antigen-specific lymphocyte reproduces copies of itself, thus forming a ______ of millions of antigen-specific cells.
(3) Within the immune system, millions of lymphocytes are undergoing this same process resulting in millions of clones for different ________.
(4) All lymphocytes in the same clone have the same ______ specificity.
(5) Clones for all possible antigens
(6) Clonal Selection = the process by which individual T & B lymphocytes are engaged by antigen and cloned to create a population of antigen-reactive cells with identical antigen specificity.
gene
clone
antigens
antigen
What are the two types of Antigen-Specific Surface Receptors?
T-Cell Receptors (TCR) or B-Cell Receptors (BCR)
Fill in the blank with regard to T-Lymphocytes:
a. These cells mature in the ______, then concentrate in lymph nodes
b. T-cell surface markers
(1) ____ – identifies mature T-cell
(2) ____ – receives activation co-signal from CD80/86 molecule on APC
(3) ____ – receptor (on CD4 cell, TH cell)– binds with CD-40 molecule on B-cell
(4) ____ – Binds to ICAM-1 and is an adhesion molecule on T-cells
c. T-cell Receptors (TCR) are antigen-specific (i.e. bind only with specific antigen for which it was programmed)
d. Subpopulations develop with specific functions [CD4=Helper (TH1, TH2), CD8=Cytotoxic (CTL), etc.] – identified by CDs present
Thymus
CD3
CD28
CD40
LFA-1
Fill in the blank with regards to B-Cells:
a. Mature in ____ _______, then concentrate in peripheral lymphoid tissues, e.g. spleen, mucosal-associated-lymphoid-tissue, lymph nodes, and bone marrow
b. CD surface markers
1) ____– significant for binding with certain T-lymphocytes
(2) ____, _____, and ____ are used for identification (others are also present)
(3) Produces ____ / ____ when B-cell acts as APC (used in binding to T-cells)
c. B-cell Receptors (BCR) are antigen-specific (cell may carry 100,000 molecules)
d. B-cells can act as _____-_______ ________ (_ _ _) by binding the antigen to the specific receptors on B-cell surface and ‘presenting’ it to T-cells
e. Upon activation, B-cells differentiate into _________ cells which manufacture immunoglobulins.
Bone marrow
CD40
CD19 / CD20 / CD21
CD80 / CD86
Antigen-Presenting Cell (APC)
plasma
Fill in the blank with regard to Antigen-Presenting Cells:
APCs possess significant surface molecules which include:
a. _ _ _- __ - carries (presents) a piece of the digested antigen – for Antigen Recognition
b. ___ /___ (formerly B7-1 & B7-2) (on B-cell) – Co-Activation molecules
c. ICAM-1 (Intercellular Adhesion Molecule-1) – the principle binding (receptor) molecule for ______ (an adhesion molecule on the T-cells)
d. LFA-3 – binding molecule for ____
MHC-II
CD80 / CD86
LFA-1 (Leukocyte Function-associated Antigen-1)
CD2
True or False:
Antigen Presenting Cells produce Interleukin-1 (IL-1) which assists with the activation of lymphocytes.
True
Fill in the Blank below…
Three examples of Antigen Presenting Cells are:
a. ____________ – Capture antigenic material, then process and present Ag on MHC-II
b. ____________ – capture antigenic material (whole microbes) via phagocytosis (See Figure 12), then digest and present Ag on MHC-II
c. ____________ – capture “digested” antigenic material from neutorphils via antigen-specific B-cell receptors (B-cells are not phagocytic) and present Ag on MHC-II
Dendritic Cells
Macrophages
B-Lymphocytes
Antigen-Presenting Cells are asisted by _______ which is produced by the lymphocytes. Examples would be macrophage-activating factor and interferon.
cytokines
Antigen-Presenting Cells produce IL- __ which enhances T-Cell development.
IL-12
What is the term to describe the small proteins that are produced by specific human cells and which act as chemical mediators of the immune system to cause or enhance certain actions or functions of the immune system?
What term is used to describe chemicals which help activate or control the cells of the immune system?
Cytokine Products of the Cells
Chemical Mediators
Adaptive Immunity Response consists of two types of responses which may interact with each other; these are defined as…?
Cell-Mediated Response
Humoral Response
Fill in the Blank:
Cell-Mediated Response: Defensive activities based on the action of pre-committed __________ that move into action to kill the invader or activate other parts of the immune system through the production of chemicals which _______ fight (act to kill) the antigen (microbe) or chemicals that help regulate the immune response.
T-Lymphocytes
DIRECTLY (“cell mediated”)
Fill in the blank below:
Humoral Response: Defensive activities based on the role of antigen-specific immunoglobulins
a. Pre-committed _____________ are activated to transform into plasma cells which produce immunoglobulins (Ig)
(1) Immunoglobulin binds to (coats) the respective antigen
(2) Leads to phagocytosis or antigen destruction
(3) Ig remains in circulating serum for months to years providing protection
b. Complement assists immunoglobulins in removing or inactivating antigens, usually by enhancing phagocytosis
B-Lymphocytes
What three major cells are involved in Cell Mediated Immunity (CMI)?
Antigen-Presenting Cells (APC)
T-Lymphocytes
Natural Killer Cells
Within the functional aspects of cell-mediated immunity, fill in the blank below regarding Natural Killer cells:
(1) Possess CD___ and CD___ surface proteins, but not CD3 (NK cells do not seem to mature in the thymus)
(2) Binding to target cells
(a) TCR is only moderately antigen-specific (fits broader spectrum of epitopes)
(b) Does not require antigen epitope to be presented on MHC-I or II molecule
(c) Binds to surface proteins & carbohydrates on target cells
(d) Binds to Fc of immunoglobulin already attached to the target cell – Antibody- Dependent Cellular Cytotoxicity (ADCC)
(3) Killing mechanism – poisoning of target cell (Similar to Cytotoxic T-Lymphocyte (CTL) below – perforin and granzymes)
(4) Roles of Natural Killer Cells
(a) Major early role in recognizing and killing virus-infected host cells and tumor cells (self)
(b) Amplify inflammatory response after bacterial infection
(c) Occasionally, activity is enhanced by IL-2 and IF – referred to as Lymphokine-Activated Killer (LAK) activity
(5) ______-_______ _____ do not acquire immune memory after initial exposure to antigen
CD16
CD56
Natural Killer Cells
